13 cm (5") Abundant across North America. In moist vegetation, swamps, stream-sides, marshes and clearings.
Dark olive upperparts.
Male: broad black mask contrasts with bright yellow underparts. Yellow undertail coverts.
Female: yellow underparts. Lacks black mask of male. Whitish eye ring.
Nests on ground.
Cocks its tail like a wren.
Song: distinctive "whitchity-whichity-whichity-witch".